For power transmission in the form of a torque from a motor, engine, turbine, or other power source to another device, such as a gear box, pump, generator, compressor or other device receiving the power, a coupling may be utilized. Such a coupling may be a single unitary component, such as a simple shaft, or an assembly of multiple components which are aligned along a common longitudinal axis. In either case, an input torque from the power source is transferred via the coupling to the gear box or other device.
In the context of a coupling assembly, each component thereof is typically a shaft element having a flange at one or both ends thereof for connection to other similarly shaped components of the assembly. The flange of each component typically has a hole pattern for receipt of a plurality of fasteners, which are typically bolts or the like. For each bolt, an associated nut is typically utilized as well. As a result, the flanges of adjacent components of the coupling assembly are interposed between a number of bolt heads and an associated nuts when fully assembled.
Unfortunately, the use of the nut for each fastener requires a relatively large amount of clearance to utilize a wrench or other device to hold the nut in place as the bolt is tightened. This large amount of clearance means that the overall outer diameter of the component which the nut seats against must be reduced to allow for said clearance. This reduction in diameter directly correlates to the maximum shaft size which a coupling can accommodate, which also directly impacts the torque density of the coupling assembly. Torque density is defined as the maximum torque capacity of the coupling assembly divided by the outermost diameter of the coupling assembly. As such, there is a need in the art for a coupling assembly with an improved connection arrangement utilized between adjacent components thereof to allow for a larger diameter of the components of the coupling assembly, which would lead to a larger bore diameter to coupling diameter ratio, as well as a greater torque density.
The invention provides such a coupling assembly. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.